Recently, for example, employees in companies have conducted business while using electronic apparatuses such as personal computers and, use of external media attachable to and detachable from the electronic apparatuses, such as USB memories and SD cards, have been prohibited by rules to prevent leakage of information.
In addition, software capable of definitely prohibiting writing of files to the external media or capable of recording logs of access to the external media have been developed, and the employees have installed such software in the personal computers used for business.
Definite prohibition of writing of files to the external media may cause troubles in business. In contrast, if the log of access to the external media is recorded, it can be confirmed later what file has been written but the writing of files itself cannot be restricted. Thus, for example, a flexible measure of permitting necessary and least files to be written is required to be taken in relation to the writing of files to the external media.